TWI742931B - Resist composition and patterning process - Google Patents

Abstract

A resist composition comprising a base polymer and an acid generator containing a sulfoniurn or iodonium salt of iodized benzamide group-containing fluorinated sulfonic acid offers a high sensitivity, minimal LWR and improved CDU independent of whether it is of positive or negative tone.

Description

Resist material and pattern forming method

The present invention relates to resist materials and pattern forming methods.

With the increasing integration and speed of LSI, the miniaturization of pattern rules is also rapidly progressing. In particular, the expansion of the logical memory market due to the spread of smartphones leads to miniaturization. As the most advanced miniaturization technology, the 10nm node device obtained by double patterning of ArF immersion lithography has been mass-produced, and the 7nm node obtained by double patterning in the next generation is also in preparation for mass production. As the 5nm node of the next generation, extreme ultraviolet (EUV) lithography can be cited as a candidate.

For EUV resist materials, it is necessary to achieve high sensitivity, high resolution and low edge roughness (LWR) at the same time. If the acid diffusion distance is shortened, the LWR will become smaller, but it will result in lower sensitivity. For example, lowering the post-exposure bake (PEB) temperature will make the LWR smaller, but will result in lower sensitivity. Increasing the amount of quencher added will also make LWR smaller, but it will result in lower sensitivity. The trade-off relationship between sensitivity and LWR must be broken.

Compared with ArF excimer laser light, EUV has a shorter wavelength of more than an order of magnitude and a higher energy density by an order of magnitude. Therefore, the number of photons exposed to the photoresist layer under EUV exposure is 1/14 compared with ArF light, which is very small. It is said that the variation of photons will cause the variation of size (LWR, uniformity of size (CDU)). Influence. In addition, due to the variation of photons, the hole pattern has a chance of not opening millions of times. According to accusations, in order to reduce the photon variation, it is necessary to increase the light absorption of the photoresist material.

It has been proposed that an acid generator that produces an acid having a benzene ring substituted with an iodine atom (Patent Documents 1 to 3). By having iodine atoms that absorb EUV light on the anion side, it has the effect of promoting the decomposition of the acid generator during EUV exposure and improving the sensitivity. However, it is necessary to further increase the sensitivity and LWR and CDU. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2018-5224 [Patent Document 2] Japanese Patent Application Publication No. 2018-25789 [Patent Document 3] Japanese Patent Application Publication No. 2019-94323

[The problem to be solved by the invention]

It is hoped to develop an acid generator that can make chemical amplification resist materials using acid as a catalyst have high sensitivity and can reduce LWR and hole pattern CDU.

The present invention is made in view of the foregoing circumstances, and aims to provide a resist material with high sensitivity and small LWR and CDU, and pattern formation using the resist material, regardless of whether it is a positive type resist material or a negative type resist material. method. [Means to solve the problem]

The inventors of the present case made diligent studies to achieve the foregoing objective and found that by using the established sulfonate or iodonium salt of fluorinated sulfonic acid containing iodinated benzamide group as an acid generator, low LWR and CDU and low contrast ratio can be obtained. The resist material with high resolution, excellent resolution and wide process margin is the completion of the present invention.

式中，m及n為滿足1≦m≦5、0≦n≦3及1≦m+n≦5的整數； p為滿足1≦p≦3的整數； L¹ 在p為1時為單鍵或碳數1~20之2價連結基，在p為2或3時為碳數1~20之3價或4價連結基，該連結基也可含有氧原子、硫原子或氮原子； Rf¹ ~Rf⁴ 各自獨立地為氫原子、氟原子或三氟甲基，但它們之中至少1個為氟原子或三氟甲基；又，Rf¹ 與Rf² 亦可合併形成羰基； R¹ 為羥基、羧基、硝基、氰基、氟原子、氯原子、溴原子、胺基、或也可含有氟原子、氯原子、溴原子、羥基、胺基或醚鍵的碳數1~20之飽和烴基、碳數1~20之飽和烴氧基、碳數2~20之飽和烴氧基羰基、碳數2~20之飽和烴基羰基氧基或碳數1~4之飽和烴基磺醯氧基，或為-NR^1A -C(=O)-R^1B 或-NR^1A -C(=O)-O-R^1B ；R^1A 為氫原子或碳數1~6之飽和烴基，也可含有鹵素原子、羥基、碳數1~6之飽和烴氧基、碳數2~6之飽和烴基羰基或飽和烴基羰基氧基；R^1B 為碳數1~16之脂肪族烴基或碳數6~12之芳基，也可含有鹵素原子、羥基、碳數1~6之飽和烴氧基、碳數2~6之飽和烴基羰基或碳數2~6之飽和烴基羰基氧基； R² 為氫原子或碳數1~4之烷基；又，R² 與L¹ 也可彼此鍵結並和它們所鍵結之氮原子一起形成環； R³ 、R⁴ 、R⁵ 、R⁶ 及R⁷ 各自獨立地為也可含有雜原子之碳數1~20之烴基；又，R³ 與R⁴ 也可彼此鍵結並和它們所鍵結之硫原子一起形成環。 2.如1.之阻劑材料，更含有有機溶劑。 3.如1.或2.之阻劑材料，其中，該基礎聚合物包含下式(a1)表示之重複單元或下式(a2)表示之重複單元； [化2]

式中，R^A 各自獨立地為氫原子或甲基； X¹ 為單鍵、伸苯基或伸萘基、或含有酯鍵、醚鍵或內酯環之碳數1~12之連結基； X² 為單鍵或酯鍵； X³ 為單鍵、醚鍵或酯鍵； R¹¹ 及R¹² 為酸不穩定基； R¹³ 為氟原子、三氟甲基、氰基、碳數1~6之飽和烴基、碳數1~6之飽和烴氧基、碳數2~7之飽和烴基羰基、碳數2~7之飽和烴基羰基氧基或碳數2~7之飽和烴氧基羰基； R¹⁴ 為單鍵或碳數1~6之烷二基，其一部分碳原子也可以取代為醚鍵或酯鍵； a為1或2；b為0~4之整數。 4.如3.之阻劑材料，更含有溶解抑制劑。 5.如3.或4.之阻劑材料，係化學增幅正型阻劑材料。 6.如1.或2.之阻劑材料，其中，該基礎聚合物不含酸不穩定基。 7.如6.之阻劑材料，更含有交聯劑。 8.如6.或7.之阻劑材料，係化學增幅負型阻劑材料。 9.如1.至8.中任一項之阻劑材料，更含有界面活性劑。 10.如1.至9.中任一項之阻劑材料，其中，該基礎聚合物更包含選自下式(f1)~(f3)表示之重複單元中之至少1種； [化3]

式中，R^A 各自獨立地為氫原子或甲基； Z¹ 為單鍵、伸苯基、-O-Z¹¹ -、-C(=O)-O-Z¹¹ -或-C(=O)-NH-Z¹¹ -；Z¹¹ 為碳數1~6之脂肪族伸烴基、伸苯基、伸萘基或將此等組合而得之碳數7~18之基，也可含有羰基、酯基、醚基或羥基； Z² 為單鍵、-Z²¹ -C(=O)-O-、-Z²¹ -O-或-Z²¹ -O-C(=O)-，Z²¹ 為碳數1~12之飽和伸烴基，也可含有羰基、酯鍵或醚鍵； Z³ 為單鍵、亞甲基、伸乙基、伸苯基、氟化伸苯基、-O-Z³¹ -、-C(=O)-O-Z³¹ -或-C(=O)-NH-Z³¹ -，Z³¹ 為碳數1~6之脂肪族伸烴基、伸苯基、氟化伸苯基、或經三氟甲基取代之伸苯基，也可含有羰基、酯鍵、醚鍵或羥基； R²¹ ~R²⁸ 各自獨立地為也可含有雜原子之碳數1~20之烴基；又，R²³ 與R²⁴ 、或R²⁶ 與R²⁷ 也可彼此鍵結並和它們所鍵結之硫原子一起形成環； R^HF 為氫原子或三氟甲基； M^- 為非親核性相對離子。 11.一種圖案形成方法，包括下列步驟： 使用如1.至10.中任一項之阻劑材料在基板上形成阻劑膜； 以高能量射線對該阻劑膜進行曝光；及 使用顯影液對該已曝光之阻劑膜進行顯影。 12.如11.之圖案形成方法，其中，該高能量射線為波長193nm之ArF準分子雷射光或波長248nm之KrF準分子雷射光。 13.如11.之圖案形成方法，其中，該高能量射線為電子束(EB)或波長3~15nm之EUV。 [發明之效果]Therefore, the present invention provides the following resist materials and pattern forming methods. 1. A resist material, comprising: a base polymer, and an acid generator, comprising a sulfonium salt represented by the following formula (A-1) or an iodonium salt represented by the following formula (A-2); [化1]

In the formula, m and n are integers satisfying 1≦m≦5, 0≦n≦3, and 1≦m+n≦5; p is an integer satisfying 1≦p≦3; L ¹ is single when p is 1. A bond or a bivalent linking group with 1-20 carbons. When p is 2 or 3, it is a trivalent or tetravalent linking group with 1-20 carbons. The linking group may also contain an oxygen atom, a sulfur atom or a nitrogen atom; Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group; in addition, Rf ¹ and Rf ² may be combined to form a carbonyl group; R ¹ is a hydroxyl group, a carboxyl group, a nitro group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an amine group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amine group, or an ether bond with a carbon number of 1 to 20 Saturated hydrocarbyl group, saturated hydrocarbyloxy group with carbon number 1-20, saturated hydrocarbyloxycarbonyl group with carbon number 2-20, saturated hydrocarbyl carbonyloxy group with carbon number 2-20 or saturated hydrocarbyloxy group with carbon number 1-4 Group, or -NR ^1A -C(=O)-R ^1B or -NR ^1A -C(=O)-OR ^1B ; R ^1A is a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms, and it may also contain a halogen atom , Hydroxy, saturated hydrocarbon group with 1 to 6 carbons, saturated hydrocarbon group with 2 to 6 carbons or saturated hydrocarbon carbonyloxy group; R ^1B is aliphatic hydrocarbon group with 1 to 16 carbons or aromatic with 6 to 12 carbons Group, which may also contain halogen atoms, hydroxyl groups, saturated hydrocarbon groups with 1 to 6 carbons, saturated hydrocarbon groups with 2 to 6 carbons, or saturated hydrocarbon groups with 2 to 6 carbons; R ² is a hydrogen atom or carbon An alkyl group of 1 to 4; In addition, R ² and L ¹ may also be bonded to each other and form a ring together with the nitrogen atom to which they are bonded; R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently It is a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms; in addition, R ³ and R ⁴ may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 2. The resist material as in 1. contains organic solvents. 3. The resist material of 1. or 2., wherein the base polymer comprises a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2); [化2]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; X ¹ is a single bond, a phenylene group or a naphthylene group, or a linking group with 1-12 carbon atoms containing an ester bond, an ether bond or a lactone ring; X ² is a single bond or an ester bond; X ³ is a single bond, an ether bond or an ester bond; R ¹¹ and R ¹² are acid labile groups; R ¹³ is a fluorine atom, trifluoromethyl, cyano group, carbon number 1~ 6 saturated hydrocarbyl groups, saturated hydrocarbyloxy groups with 1 to 6 carbons, saturated hydrocarbyl carbonyl groups with 2 to 7 carbons, saturated hydrocarbyl carbonyloxy groups with 2 to 7 carbons, or saturated hydrocarbyloxycarbonyl groups with 2 to 7 carbons; R ¹⁴ is a single bond or an alkanediyl group with 1 to 6 carbon atoms, some of its carbon atoms may also be substituted with ether bonds or ester bonds; a is 1 or 2; b is an integer of 0-4. 4. The resist material as in 3. contains a dissolution inhibitor. 5. The resist material of 3. or 4. is a chemically amplified positive resist material. 6. The resist material of 1. or 2., wherein the base polymer does not contain an acid labile group. 7. The resist material as in 6. contains a cross-linking agent. 8. The resist material of 6. or 7. is a chemically amplified negative resist material. 9. The resist material of any one of 1. to 8. further contains a surfactant. 10. The resist material according to any one of 1. to 9., wherein the base polymer further comprises at least one of the repeating units represented by the following formulas (f1) to (f3); [化3]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, a phenylene group, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -; Z ¹¹ is aliphatic alkylene group, phenylene group, naphthylene group with carbon number 1 to 6, or a combination of these, and the group with carbon number 7 to 18, and can also contain carbonyl group, ester group, ether or a hydroxyl group; Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 is a carbon number of 1 to 12 Saturated alkylene group may also contain carbonyl, ester bond or ether bond; Z ³ is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, -OZ ³¹ -, -C(=O) -OZ ³¹ -or -C(=O)-NH-Z ³¹ -, Z ³¹ is aliphatic alkylene group, phenylene group, fluorinated phenylene group with carbon number 1~6, or substituted with trifluoromethyl The phenylene group may also contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group; R ²¹ to R ²⁸ are each independently a hydrocarbon group of 1 to 20 carbons that may also contain heteroatoms; and R ²³ and R ²⁴ , or R ²⁶ and R ²⁷ can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded; R ^HF is a hydrogen atom or a trifluoromethyl group; M ^{-is a} non-nucleophilic counter ion. 11. A pattern forming method, comprising the following steps: forming a resist film on a substrate using the resist material of any one of 1. to 10.; exposing the resist film with high-energy rays; and using a developer The exposed resist film is developed. 12. The pattern forming method of 11., wherein the high-energy rays are ArF excimer laser light with a wavelength of 193 nm or KrF excimer laser light with a wavelength of 248 nm. 13. The pattern forming method according to 11., wherein the high-energy ray is electron beam (EB) or EUV with a wavelength of 3-15 nm. [Effects of Invention]

The sulfonium salt or iodine salt of fluorinated sulfonic acid containing iodinated benzamide group has the characteristics of low acid diffusion because of the large atomic weight of iodine atoms and the ability to control the diffusion of amino acid. In addition, the absorption of iodine atoms for EUV with a wavelength of 13.5nm is very large, so secondary electrons will be generated from iodine atoms during exposure, and the sensitivity will be improved. In this way, a resist material with high sensitivity, low LWR and low CDU can be constructed.

[Resist material] The resist material of the present invention contains a base polymer and an acid generator containing a sulfonic acid salt or an iodonium salt of a fluorinated sulfonic acid containing an iodinated benzamide group. The aforesaid sulfonium salt and iodonium salt are acid generators that generate fluorinated sulfonic acid containing iodinated benzamide groups due to light exposure. In the resist material of the present invention, an acid generator that generates sulfonic acid, imidic acid, or methylated acid, which is different from the above-mentioned acid generator, may be added, or it may be combined with a bonding acid that is bonded to the base polymer. Producer combination.

If the light is mixed with the sulfonic acid salt of fluorinated sulfonic acid containing iodinated benzamide group and the weaker acid or sulfonic acid salt of carboxylic acid, it will produce iodinated benzyl sulfonic acid. Amino fluorinated sulfonic acid, and weaker acid or carboxylic acid. The acid generator does not decompose completely, so there is an undecomposed acid generator nearby. Here, if a fluorinated sulfonic acid containing an iodinated benzamide group, a weaker acid and a sulfonic acid salt of a carboxylic acid coexist, a fluorinated sulfonic acid containing an iodinated benzamide group will occur. , Ion exchange with weak acid sulfonic acid and carboxylic acid sulfonic acid salt to generate fluorinated sulfonic acid sulfonic acid salt containing iodinated benzamide group and release weak acid sulfonic acid and carboxylic acid. This is due to the fact that fluorinated sulfonates containing iodinated benzamide groups, which are stronger in terms of acid, are more stable. On the other hand, even if there are sulfonic acid salts of fluorinated sulfonic acid containing iodinated benzamide groups, and weak acids such as sulfonic acid and carboxylic acid, ion exchange will not occur. The ion exchange, which depends on the order of acid strength, will not only occur in the case of sulphur salt, but also in the case of sulphur salt. The weak acid sulphur salt and iodonium salt, when combined with the acid generator of fluorosulfonic acid, function as a quencher. In addition, iodine atoms absorb EUV with a wavelength of 13.5 nm extremely, so secondary electrons are generated during exposure, and the energy of the secondary electrons moves to the acid generator to promote decomposition, thereby increasing the sensitivity. In particular, when the substitution number of iodine atoms is 2 or more, this effect is high.

In order to improve LWR, it is effective to suppress aggregation of polymers and acid generators. In order to inhibit the aggregation of the polymer, it is effective to reduce the gap between hydrophobicity and hydrophilicity, lower the glass transition point (Tg), and lower the molecular weight of the polymer. Specifically, it is effective to reduce the polarity gap between the hydrophobic acid-labile group and the hydrophilic adhesive group, and to use compact adhesive groups such as monocyclic lactones to lower Tg. In order to suppress the aggregation of the acid generator, it is effective to introduce a substituent group into the cation of triphenylaluminium. In particular, for the methacrylate polymer for ArF formed of an alicyclic protecting group and an adhesive group of a lactone, only triphenylaluminum formed of an aromatic group has a heterogeneous structure, and the compatibility is low. Regarding the substituents introduced into the triphenylaluminium, the same alicyclic groups or lactones as those used for the base polymer are conceivable. Since the sulfonium salt is hydrophilic, when the lactone is introduced, the hydrophilicity will become too high, the compatibility with the polymer will be reduced, and the agglomeration of the sulfonium salt will occur. If the hydrophobic alkyl group is introduced, the sulfonium salt can be uniformly dispersed in the resist film. In International Publication No. 2011/048919, a method for improving LWR by introducing an alkyl group into a salt of sulfimidic acid which is fluorinated at the α-position is proposed.

The aforesaid sulfonate or iodonium salt of fluorinated sulfonic acid containing iodinated benzamide group has a large atomic weight iodine atom introduced into the anion and an amide group that controls acid diffusion, so the acid diffusion is small and it is in phase with the polymer The capacitance is also high and the dispersibility is excellent, thereby improving LWR and CDU. Since the amide group has high hydrophilicity, it also has the effect of offsetting the decrease in the solubility of the alkali developer caused by the iodine atom.

The aforementioned improvement effect of LWR and CDU obtained by the fluorinated sulfonic acid salt or iodonium salt containing the iodinated benzamide group is used in the positive pattern formation, negative pattern formation, or in the organic solvent by the development of the alkali aqueous solution. The negative pattern formation during development is effective.

[Sulphur salt and sulphur salt of fluorinated sulfonic acid containing iodinated benzamide group] The sulphur salt and sulphur salt contained in the resist material of the present invention are respectively the following formulas (A-1) and (A-2) ) Expresser. [化4]

In formulas (A-1) and (A-2), m and n are integers satisfying 1≦m≦5, 0≦n≦3, and 1≦m+n≦5. p is an integer satisfying 1≦p≦3.

In formulas (A-1) and (A-2), ^{when p is 1, L 1} is a single bond or a divalent linking group with 1 to 20 carbons, and when p is 2 or 3, it is a single bond with 1 to 20 carbons. A trivalent or tetravalent linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

In formulas (A-1) and (A-2), Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. In addition, Rf ¹ and Rf ² may be combined to form a carbonyl group.

In formulas (A-1) and (A-2), R ¹ is a hydroxyl group, a carboxyl group, a nitro group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, or may also contain a fluorine atom, a chlorine atom, and a bromine Atom, hydroxyl, amine or ether bond saturated hydrocarbon group with 1 to 20 carbons, saturated hydrocarbon group with 1 to 20 carbons, saturated hydrocarbon oxycarbonyl group with 2 to 20 carbons, saturated hydrocarbon group with 2 to 20 carbons Carbonyloxy or saturated hydrocarbon sulfonyloxy with 1 to 4 carbons, or -NR ^1A -C(=O)-R ^1B or -NR ^1A -C(=O)-OR ^1B . R ^1A is a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbons, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon group with 1 to 6 carbons, a saturated hydrocarbon group with 2 to 6 carbons, or a saturated hydrocarbon carbonyloxy group. R ^1B is an aliphatic hydrocarbon group with 1 to 16 carbons or an aryl group with 6 to 12 carbons. It may also contain halogen atoms, hydroxyl groups, saturated hydrocarbon groups with 1 to 6 carbons, and saturated hydrocarbon groups with 2 to 6 carbons. Or saturated hydrocarbyl carbonyloxy with 2-6 carbons.

The saturated hydrocarbon group with 1 to 20 carbon atoms represented by R ¹ may be any of linear, branched, and cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, and n-propyl. Butyl, isobutyl, second butyl, tertiary butyl, n-pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, Alkyl groups such as n-undecyl, n-dodecyl, n-tridecyl, n-pentadecyl and n-hexadecyl; cyclopentyl, cyclohexyl and other cyclic saturated hydrocarbon groups. Examples of the saturated hydrocarbon group having 1 to 6 carbons represented by R ^1A include those having 1 to 6 carbons in the aforementioned saturated hydrocarbon group. In addition, as the saturated hydrocarbon group of the aforementioned saturated hydrocarbon group, saturated hydrocarbon oxycarbonyl group, saturated hydrocarbon group carbonyloxy group, and saturated hydrocarbon group sulfonyloxy group, the same saturated hydrocarbon group as the one having the predetermined carbon number in the specific examples of the aforementioned saturated hydrocarbon group can be mentioned. .

The aliphatic hydrocarbon group having 1 to 16 carbon atoms represented by R ^1B may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-pentyl, neopentyl, n-hexyl, n-propyl Heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-pentadecyl, n-hexadecyl Alkyl groups such as cyclopentyl, cyclohexyl and other cyclic saturated hydrocarbon groups; vinyl, 1-propenyl, 2-propenyl, butenyl, hexenyl and other alkenyl groups; cyclohexenyl and other cyclic unsaturated hydrocarbon groups Wait. The aryl group having 6 to 12 carbon atoms represented by R ^1B includes phenyl, tolyl, xylyl, 1-naphthyl, 2-naphthyl and the like.

In the formulas (A-1) and (A-2), R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In addition, R ² and L ¹ may be bonded to each other and form a ring together with the nitrogen atom to which they are bonded. Examples of the alkyl group having 1 to 4 carbon atoms represented by R ² include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, and tertiary butyl.

In formulas (A-1) and (A-2), R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a hydrocarbon group with 1 to 20 carbon atoms that may contain a hetero atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-pentyl, n-hexyl, n-octyl, n- Nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, eicosan Alkyl groups with 1 to 20 carbon atoms; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, adamantyl, etc. 3-20 cyclic saturated hydrocarbon groups; vinyl, propenyl, butenyl, hexenyl and other alkenyl groups with 2-20 carbons; cyclohexenyl, norbornyl and other cyclic saturated hydrocarbon groups with 2-20 carbons Unsaturated aliphatic hydrocarbon group; ethynyl, propynyl, butynyl and other alkynyl groups with 2 to 20 carbon atoms; phenyl, methyl phenyl, ethyl phenyl, n-propyl phenyl, isopropyl phenyl , N-butyl phenyl, isobutyl phenyl, second butyl phenyl, tertiary butyl phenyl, naphthyl, methyl naphthyl, ethyl naphthyl, n-propyl naphthyl, isopropyl naphthalene Aryl groups with 6 to 20 carbon atoms, such as butyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tertiary butylnaphthyl; Aralkyl; a base obtained by combining them, etc. In addition, part of the hydrogen atoms of these groups may be substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, and some of the carbon atoms of these groups may be substituted with oxygen atoms, sulfur atoms, nitrogen atoms, etc. The heteroatom group, as a result, may also contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, and the like.

式中，虛線為和R⁵ 之原子鍵。In addition, R ³ and R ⁴ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, the aforementioned ring should preferably have the structure shown below. [化5]

In the formula, the dotted line is the atomic bond ^{with R 5.}

Among the aforesaid sulphur salts and sulphur salts, especially those represented by the following formula (A-1-1) and the following formula (A-2-1), EUV has a large absorption, high sensitivity and low LWR or low CDU The view is more ideal. [化6]

In formulas (A-1-1) and (A-2-1), R ³ , R ⁴ , R ⁵ , R ⁶ and R ^{7 are the} same as described above. R is an iodine atom or a hydroxyl group. L ² is a single bond or an alkanediyl group with 1 to 6 carbon atoms. The aforementioned alkanediyl groups with 1 to 6 carbon atoms include: methylene, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1, 2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3- Diyl, butane-1,4-diyl, butane-2,2-diyl, butane-2,3-diyl, pentane-1,5-diyl, hexane-1,6- Second base and so on.

The cations of the alumium salt represented by the formula (A-1) include those shown below, but are not limited to these. [化7]

[化8]

[化9]

[化10]

[化11]

[化12]

[化13]

[化14]

[化15]

[化16]

[化17]

[化18]

[化19]

[化20]

[化21]

[化22]

[化23]

[化24]

[化25]

[化26]

[化27]

[化28]

[化29]

[化30]

[化31]

[化32]

[化33]

[化34]

[化35]

[化36]

[化37]

[化38]

[化39]

[化40]

[化41]

[化42]

[化43]

[化44]

[化45]

[化46]

The cations of the iodonium salt represented by the formula (A-2) include those shown below, but are not limited to these. [化47]

The anions of the sulphur salt represented by the formula (A-1) and the iodonium salt represented by the formula (A-2) include those shown below, but are not limited to these. [化48]

[化49]

[化50]

[化51]

[化52]

[化53]

[化54]

[化55]

[化56]

[化57]

[化58]

[化59]

[化60]

[化61]

[化62]

[化63]

[化64]

[化65]

[化66]

[化67]

As a method of synthesizing the sulfonium salt represented by the formula (A-1) and the iodonium salt represented by the formula (A-2), there may be exemplified sulfonic acid which is weaker than the fluorinated sulfonic acid containing an iodinated benzamide group. A method of ion exchange with salt or iodonium salt. Examples of acids weaker than fluorinated sulfonic acids containing iodinated benzamide groups include carbonic acid. In addition, it can also be synthesized by ion-exchanging sodium salt or ammonium salt of fluorinated sulfonic acid containing iodinated benzamide group with cerium chloride or iodonium chloride.

In the resist material of the present invention, the content of the sulfonium salt represented by the formula (A-1) or the iodonium salt represented by the formula (A-2) is based on 100 parts by mass of the base polymer described later, considering the sensitivity and the effect of inhibiting acid diffusion The viewpoint is preferably 0.01 to 1,000 parts by mass, more preferably 0.05 to 500 parts by mass.

式(a1)及(a2)中，R^A 各自獨立地為氫原子或甲基。X¹ 為單鍵、伸苯基或伸萘基、或含有酯鍵、醚鍵或內酯環之碳數1~12之連結基。X² 為單鍵或酯鍵。X³ 為單鍵、醚鍵或酯鍵。R¹¹ 及R¹² 為酸不穩定基。R¹³ 為氟原子、三氟甲基、氰基、碳數1~6之飽和烴基、碳數1~6之飽和烴氧基、碳數2~7之飽和烴基羰基、碳數2~7之飽和烴基羰基氧基或碳數2~7之飽和烴氧基羰基。R¹⁴ 為單鍵或碳數1~6之烷二基，其一部分碳原子也可以取代為醚鍵或酯鍵。a為1或2。b為0~4之整數。[Base polymer] The base polymer contained in the resist material of the present invention, in the case of a positive type resist material, contains a repeating unit containing an acid-labile group. The repeating unit containing an acid-labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1.) or a repeating unit represented by formula (a2) (hereinafter also referred to as repeating unit a2.) . [化68]

In formulas (a1) and (a2), R ^{A is} each independently a hydrogen atom or a methyl group. X ¹ is a single bond, a phenylene group or a naphthylene group, or a linking group with 1-12 carbon atoms containing an ester bond, an ether bond or a lactone ring. X ² is a single bond or an ester bond. X ³ is a single bond, ether bond or ester bond. R ¹¹ and R ¹² are acid labile groups. R ¹³ is a fluorine atom, a trifluoromethyl group, a cyano group, a saturated hydrocarbon group with 1 to 6 carbons, a saturated hydrocarbon group with 1 to 6 carbons, a saturated hydrocarbon group with 2 to 7 carbons, and a carbonyl group with 2 to 7 carbons. Saturated hydrocarbyl carbonyloxy group or saturated hydrocarbyloxy carbonyl group with 2-7 carbons. R ¹⁴ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and some of its carbon atoms may be substituted with ether bonds or ester bonds. a is 1 or 2. b is an integer from 0 to 4.

The monomers that provide the repeating unit a1 include those shown below, but are not limited to these. In addition, in the following formula, R ^A and R ^{11 are the} same as described above. [化69]

The monomers providing the repeating unit a2 can be listed below, but are not limited to these. In addition, in the following formula, R ^A and R ^{12 are the} same as described above. [化70]

^{The acid labile groups represented by R 11} and R ¹² in the repeating units a1 and a2 include, for example, those described in JP 2013-80033 A and JP 2013-83821 A.

式中，虛線為原子鍵。Typically, the acid labile group can be represented by the following formulas (AL-1) to (AL-3). [化71]

In the formula, the dashed line is an atomic bond.

In formulas (AL-1) and (AL-2), R ^L1 and R ^L2 are each independently a hydrocarbon group having 1 to 40 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned hydrocarbon group is preferably a saturated hydrocarbon group with 1 to 40 carbon atoms, more preferably a saturated hydrocarbon group with 1 to 20 carbon atoms.

In formula (AL-1), c is an integer from 0 to 10, preferably an integer from 1 to 5.

In the formula (AL-2), R ^L3 and R ^L4 are each independently a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned hydrocarbon group is preferably a saturated hydrocarbon group with 1 to 20 carbon atoms. In addition, ^{any two of R L2} , R ^L3 and R ^L4 may be bonded to each other and form a ring with 3 to 20 carbon atoms together with the carbon atom or carbon atom and oxygen atom to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

In the formula (AL-3), R ^L5 , R ^L6 and R ^L7 are each independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned hydrocarbon group is preferably a saturated hydrocarbon group with 1 to 20 carbon atoms. In addition, ^{any two of R L5} , R ^L6 and R ^L7 may be bonded to each other and form a ring with 3 to 20 carbon atoms together with the carbon atom to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

The aforementioned base polymer may further include a repeating unit b containing a phenolic hydroxyl group as an adhesive group. The monomers that provide the repeating unit b include those shown below, but are not limited to these. In addition, in the following formula, R ^{A is the} same as described above. [化72]

The aforementioned base polymer may further include a repeating unit c containing a hydroxyl group other than a phenolic hydroxyl group, a lactone ring, an ether bond, an ester bond, a carbonyl group, or a cyano group as another adhesive group. The monomers that provide the repeating unit c may be those shown below, but are not limited to them. In addition, in the following formula, R ^{A is the} same as described above. [化73]

[化74]

[化75]

[化76]

[化77]

[化78]

[化79]

[化80]

The aforementioned base polymer may further include repeating units d derived from indene, benzofuran, benzothiophene, vinyl naphthalene, chromone, coumarin, norbornadiene, or derivatives thereof. The monomers that provide the repeating unit d can be listed below, but are not limited to them. [化81]

The aforementioned base polymer may further include a repeating unit e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene dihydroindene, vinyl pyridine, or vinyl carbazole.

The aforementioned base polymer may further include a repeating unit f derived from an onium salt containing a polymerizable olefin. Japanese Patent Laid-Open No. 2005-84365 proposes sulfonic acid salts and iodonium salts containing polymerizable olefins that produce specific sulfonic acids. Japanese Patent Application Publication No. 2006-178317 proposes a sulfonic acid salt in which sulfonic acid is directly bonded to the main chain.

Preferable repeating unit f includes repeating units represented by the following formula (f1) (hereinafter also referred to as repeating unit f1.), repeating units represented by the following formula (f2) (hereinafter also referred to as repeating unit f2.) and the following The repeating unit represented by the formula (f3) (hereinafter, also referred to as repeating unit f3). In addition, the repeating units f1 to f3 may be used singly or in combination of two or more kinds. [化82]

Formula (f1) ~ (f3) in, R ^A is independently a hydrogen atom or a methyl group. Z ¹ is a single bond, phenylene, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH-Z ¹¹ -. Z ¹¹ is an aliphatic alkylene group, phenylene group, naphthylene group with 1 to 6 carbon atoms, or a combination of these, and a group with carbon number 7 to 18, and may also contain a carbonyl group, an ester group, an ether group or a hydroxyl group. Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 is a C 1-12 saturated hydrocarbon group of extension, It may also contain a carbonyl group, an ester bond or an ether bond. Z ³ is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, -OZ ³¹ -, -C(=O)-OZ ³¹ -or -C(=O)-NH-Z ³¹ -, Z ³¹ is an aliphatic alkylene group, phenylene group, fluorinated phenylene group, or a phenylene group substituted by trifluoromethyl group with carbon number 1~6. It can also contain a carbonyl group, an ester bond, an ether bond or Hydroxy. In addition, the aforementioned aliphatic alkylene group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned saturated alkylene group may be any of linear, branched, and cyclic.

In formulas (f1) to (f3), R ²¹ to R ²⁸ are each independently a hydrocarbon group with 1 to 20 carbon atoms that may contain a hetero atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and a group obtained by combining them. These specific examples include the same groups as those exemplified in the description ^{of R 3} , R ⁴ , R ⁵ , R ⁶ and R ⁷ in formulas (A-1) and (A-2). In addition, some or all of the hydrogen atoms of these groups may be substituted with saturated hydrocarbon groups with 1 to 10 carbons, halogen atoms, trifluoromethyl, cyano, nitro, hydroxyl, mercapto, and saturated hydrocarbons with 1 to 10 carbons. An oxy group, a saturated hydrocarbyloxycarbonyl group having 2 to 10 carbons, or a saturated hydrocarbyloxycarbonyl group having 2 to 10 carbons, some of the carbon atoms of these groups may be substituted with carbonyl groups, ether bonds or ester bonds. In addition, R ²³ and R ²⁴ or R ²⁶ and R ²⁷ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring includes the same ring as exemplified in the description of the formula (A-1) regarding the ring that R ³ and R ⁴ can be bonded to each other and formed together with the sulfur atom to which they are bonded.

In the formula (f2), R ^HF is a hydrogen atom or a trifluoromethyl group.

In formula (f1), M ^{-is a} non-nucleophilic relative ion. The aforementioned non-nucleophilic relative ions include: halide ions such as chloride ion and bromide ion; trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion, nonafluorobutanesulfonate ion Isofluoroalkylsulfonate ion; toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, 1,2,3,4,5-pentafluorobenzenesulfonate ion and other arylsulfonate ion; Alkylsulfonate ions such as sulfonate ion and butanesulfonate ion; bis(trifluoromethylsulfonyl) iminium ion, bis(perfluoroethylsulfonyl) iminium ion, bis(perfluoromethylsulfonyl) Butylsulfonyl) iminium ion and other iminium ions; ginseng (trifluoromethyl sulfonyl) methide ion, ginseng (perfluoroethyl sulfonyl) methide ion and other methide ions .

The aforementioned non-nucleophilic relative ions can further include the sulfonic acid ion represented by the following formula (f1-1) substituted with a fluorine atom at the α position, and the α position represented by the following formula (f1-2) substituted with a fluorine atom and the β position represented by Fluoromethyl substituted sulfonic acid ion, etc. [化83]

In the formula (f1-1), R ³¹ is a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms, and may also contain an ether bond, an ester bond, a carbonyl group, a lactone ring or a fluorine atom.

In the formula (f1-2), R ³² is a hydrogen atom, a hydrocarbon group with 1 to 30 carbons, or a hydrocarbon group with 2 to 30 carbons. It may also contain an ether bond, an ester bond, a carbonyl group or a lactone ring.

The hydrocarbon group of the hydrocarbyl group and hydrocarbyl carbonyl group represented by R ³¹ or R ³² may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, second butyl, tertiary butyl, pentyl, neopentyl, hexyl, heptyl, 2- Ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, eicosyl and other alkyl groups; cyclopentyl, cyclohexyl, 1-adamantyl, 2- Adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, dicyclohexylmethyl and other rings Saturated hydrocarbon groups of formula; alkenyl groups such as allyl groups; cyclic unsaturated hydrocarbon groups such as 3-cyclohexenyl groups; aryl groups such as phenyl, 1-naphthyl and 2-naphthyl groups; aromatic groups such as benzyl and diphenylmethyl Alkyl and so on.

In addition, part or all of the hydrogen atoms in these groups may be substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the carbon atoms of these groups may be substituted with oxygen atoms, sulfur atoms, The group of heteroatoms such as nitrogen atom, as a result, may also contain hydroxyl, cyano, carbonyl, ether bond, ester bond, sulfonate bond, carbonate group, lactone ring, sultone ring, carboxylic anhydride, haloalkane Base and so on. Hydrocarbon groups containing heteroatoms include: tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy) Methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl and the like.

The cations of the monomers providing the repeating unit f1 include those shown below, but are not limited to these. In addition, in the following formula, R ^{A is the} same as described above. [化84]

Specific examples of the cations of the monomers providing the repeating unit f2 or f3 include the same cations as those exemplified for the cation of the sulfonium salt represented by the formula (A-1).

Examples of the anion of the monomer providing the repeating unit f2 include those shown below, but are not limited to these. In addition, in the following formula, R ^{A is the} same as described above. [化85]

[化86]

Examples of the anion of the monomer providing the repeating unit f3 include those shown below, but are not limited to these. In addition, in the following formula, R ^{A is the} same as described above. [化87]

[化88]

[化89]

By bonding the acid generator to the polymer backbone, the acid diffusion can be reduced and the resolution degradation caused by the blurring of the acid diffusion can be prevented. In addition, by uniformly dispersing the acid generator, LWR is improved.

The basic polymer used for the positive resist material has a repeating unit a1 or a2 containing an acid-labile group as an essential unit. At this time, the content ratios of the repeating units a1, a2, b, c, d, e, and f are preferably 0≦a1<1.0, 0≦a2<1.0, 0<a1+a2<1.0, 0≦b≦0.9, 0 ≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5, which are 0≦a1≦0.9, 0≦a2≦0.9, 0.1≦a1+a2≦0.9, 0≦b≦0.8, 0≦c≦0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4 are more preferably 0≦a1≦0.8, 0≦a2≦0.8, 0.1≦a1+a2≦0.8, 0≦b ≦0.75, 0≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0≦f≦0.3 are more preferable. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f3, f=f1+f2+f3. Also, a1+a2+b+c+d+e+f=1.0.

On the other hand, in the base polymer for the negative resist material, the acid-labile group is not necessary. Such a base polymer may include a repeating unit b, and if necessary, a repeating unit c, d, e, and/or f. The content ratio of these repeating units is preferably 0<b≦1.0, 0≦c≦0.9, 0≦d≦0.8, 0≦e≦0.8, and 0≦f≦0.5, which is 0.2≦b≦1.0, 0≦c≦ 0.8, 0≦d≦0.7, 0≦e≦0.7, and 0≦f≦0.4 are more preferably 0.3≦b≦1.0, 0≦c≦0.75, 0≦d≦0.6, 0≦e≦0.6, and 0≦f ≦0.3 is better. In addition, when the repeating unit f is at least one selected from the repeating units f1 to f3, f=f1+f2+f3. Also, b+c+d+e+f=1.0.

In order to synthesize the aforementioned base polymer, for example, the monomer providing the aforementioned repeating unit is added, a radical polymerization initiator is added to an organic solvent, and the polymerization is carried out by heating.

Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Examples of polymerization initiators: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2-azobis(2 -Methyl propionate) dimethyl, benzyl peroxide, laurel peroxide, etc. The temperature during polymerization should be 50~80℃. The reaction time is preferably 2-100 hours, more preferably 5-20 hours.

When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be first substituted with acetal groups that are easily deprotected by acids such as ethoxyethoxy groups during polymerization. After polymerization, they can be deprotected with weak acids and water. It can be substituted with acetyl, methyl acetyl, trimethyl acetyl, etc., and then undergo alkaline hydrolysis after polymerization.

When hydroxystyrene and hydroxyvinylnaphthalene are copolymerized, acetoxystyrene and acetoxyvinylnaphthalene can be used instead of hydroxystyrene and hydroxyvinylnaphthalene. The oxy group is deprotected and becomes hydroxystyrene and hydroxyvinylnaphthalene.

As the base for alkaline hydrolysis, ammonia, triethylamine, etc. can be used. In addition, the reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

Regarding the aforementioned base polymer, the polystyrene conversion weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) using THF as a solvent is preferably 1,000 to 500,000, and more preferably 2,000 to 30,000. If the Mw is too small, the heat resistance of the resist material will be poor, and if it is too large, the alkali solubility will decrease and tailing is likely to occur after pattern formation.

In addition, when the molecular weight distribution (Mw/Mn) of the aforementioned base polymer is wide, low-molecular-weight and high-molecular-weight polymers may exist. Therefore, foreign matter may appear on the pattern after exposure, or the shape of the pattern may deteriorate. As the pattern rule becomes finer, the influence of Mw and Mw/Mn tends to increase. Therefore, in order to obtain a resist material suitable for fine pattern size, the Mw/Mn of the aforementioned base polymer is preferably 1.0~2.0, 1.0~1.5 The narrow dispersion is particularly good.

The aforementioned base polymer may also include two or more polymers having different composition ratios, Mw, and Mw/Mn.

[Other ingredients] In addition to containing the aforementioned components, an acid generator other than the sulphur salt represented by the formula (A-1) or the iodonium salt represented by the formula (A-2) (hereinafter referred to as other acid generators) is appropriately combined and blended according to the purpose. ), organic solvents, surfactants, dissolution inhibitors, cross-linking agents, etc. to form a positive resist material or a negative resist material, whereby the exposure part due to the catalyst reaction causes the aforementioned base polymer to react to the developer The dissolution rate is accelerated, so it can be made into a very high-sensitivity positive or negative resist material. At this time, the dissolution contrast and resolution of the resist film are high, there is exposure margin, the process adaptability is excellent, the pattern shape after exposure is good, and the diffusion of the acid is particularly suppressed, so the density difference is small, so it can be made practical High, it is a very effective resist material as a resist material for ultra LSI. In particular, if it is made into a chemically amplified positive resist material that utilizes an acid catalyst reaction, it can be made into a higher-sensitivity resist material, and it is also a resist material with more excellent properties, which is extremely useful.

Examples of the aforementioned other acid generators include compounds (photoacid generators) that generate acid in response to active light or radiation. As for the components of the photoacid generator, it does not matter as long as it is a compound that generates acid due to high-energy ray irradiation, and it is preferably an acid generator that generates sulfonic acid, imidic acid, or methylated acid. Preferable photoacid generators include sulfonium salt, iodonium salt, sulfodiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generator and the like. Specific examples of acid generators are described in paragraphs [0122] to [0142] of Japanese Patent Application Publication No. 2008-111103, Japanese Patent Application Publication No. 2018-5224, and Japanese Patent Application Publication No. 2018-25789. In the resist material of the present invention, the content of other acid generators relative to 100 parts by mass of the base polymer is preferably 0 to 200 parts by mass, preferably 0.1 to 100 parts by mass.

As the aforementioned organic solvent, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone and the like described in paragraphs [0144] to [0145] of JP 2008-111103 A, 3-methyl Alcohols such as oxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, propylene glycol monomethyl Ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether and other ethers, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tertiary butyl acetate, tertiary butyl propionate, propylene glycol single tertiary Esters such as butyl ether acetate, lactones such as γ-butyrolactone, and mixed solvents thereof. In the resist material of the present invention, the content of the organic solvent relative to 100 parts by mass of the base polymer is preferably 100 to 10,000 parts by mass, and more preferably 200 to 8,000 parts by mass.

Examples of the aforementioned surfactant include those described in paragraphs [0165] to [0166] of JP 2008-111103 A. By adding a surfactant, the coatability of the resist material can be further improved or controlled. In the resist material of the present invention, the content of the surfactant is preferably 0.0001-10 parts by mass relative to 100 parts by mass of the base polymer.

When the resist material of the present invention is a positive type, by blending a dissolution inhibitor, the gap between the dissolution speed of the exposed part and the unexposed part can be further increased, and the resolution can be further improved. The aforementioned dissolution inhibitors include: the molecular weight is preferably 100 to 1,000, more preferably 150 to 800, and the hydrogen atom of the phenolic hydroxyl group of the compound containing two or more phenolic hydroxyl groups in the molecule is 0 to 100 as a whole The hydrogen atom of the carboxyl group of the compound obtained by substituting the acid labile group with the ratio of mol% or the compound containing a carboxyl group in the molecule is substituted with the acid labile group at an average ratio of 50-100 mol% on the whole The compound obtained afterwards. Specifically, bisphenol A, ginseng phenol, phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, cholic acid, and the hydrogen atom of the carboxyl group are substituted with acid labile groups. , For example, it is described in paragraphs [0155]~[0178] of JP 2008-122932 A.

When the resist material of the present invention is a positive resist material, the content of the dissolution inhibitor relative to 100 parts by mass of the base polymer is preferably 0-50 parts by mass, more preferably 5-40 parts by mass.

On the other hand, when the resist material of the present invention is a negative type, by adding a cross-linking agent to reduce the dissolution speed of the exposed part, a negative pattern can be obtained. The aforementioned crosslinking agent includes: epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds, or urea substituted with at least one group selected from methylol, alkoxymethyl, and oxymethyl Compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyl ether groups, etc. These can be used as additives, and can also be introduced into the polymer side chain as a pendant group. In addition, a compound containing a hydroxyl group can also be used as a crosslinking agent.

The aforementioned epoxy compounds include: ginseng (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, trihydroxyethyl Ethane triglycidyl ether and so on.

The aforementioned melamine compounds include: hexamethylol melamine, hexamethoxymethyl melamine, compounds obtained by methoxymethylating 1 to 6 methylol groups in hexamethylol melamine, or mixtures thereof, Hexamethoxyethyl melamine, hexamethyloloxymethyl melamine, compounds obtained by oxymethylating 1 to 6 methylol groups in hexamethylol melamine, or mixtures thereof, etc.

Guanamine compounds include: tetramethylolguanamine, tetramethoxymethylguanamine, and compounds obtained by methoxymethylating 1 to 4 methylol groups in tetramethylolguanamine Or a mixture thereof, tetramethoxyethylguanamine, tetrahydroxyguanamine, a compound obtained by oxymethylating 1 to 4 methylol groups in tetramethylolguanamine or Mixtures and so on.

The glycoluril compounds include: tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethyl glycoluril, and 1 to 4 methylol groups in tetramethylol glycoluril are given methoxymethyl Compounds or mixtures obtained after radicalization, compounds or mixtures obtained after oxymethylation of 1 to 4 methylol groups in tetramethylol glycoluril, etc. Urea compounds include: tetramethylolurea, tetramethoxymethylurea, compounds obtained by methoxymethylating 1 to 4 methylol groups in tetramethylolurea, or mixtures thereof, Tetramethoxyethyl urea and the like.

Examples of the isocyanate compound include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, and the like.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylenebisazide, 4,4'-oxybisazide, and the like.

Compounds containing alkenyl ether groups include: ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether Ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanedi Alcohol divinyl ether, neopentaerythritol trivinyl ether, neopentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane trivinyl ether, etc. .

When the resist material of the present invention is a negative resist material, the content of the crosslinking agent is preferably 0.1-50 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 1-40 parts by mass.

Quenchers can also be blended in the resist material of the present invention. Examples of the aforementioned quencher include conventional basic compounds. Conventional basic compounds include: 1, 2, 3, aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, and those with sulfonyl groups Nitrogen-containing compounds, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imines, urethanes, etc. In particular, the amine compounds of the first, second, and third levels described in paragraphs [0146] to [0164] of JP 2008-111103 A, especially those having a hydroxyl group, an ether bond, an ester bond, a lactone ring, and a cyano group , Amine compounds with sulfonate groups or compounds with urethane groups described in Japanese Patent No. 3790649 are preferable. By adding such a basic compound, for example, the diffusion rate of the acid in the resist film can be further suppressed, or the shape can be corrected.

In addition, examples of the quenching agent include onium salts such as sulfonic acid and carboxylic acid that are not fluorinated at the α-position, such as sulfonic acid, iodonium salt, and ammonium salt. In order to deprotect the acid labile group of the carboxylic acid ester, a fluorinated sulfonic acid, imine acid or methylated acid at the α position is necessary, but it is exchanged with a salt of an onium salt that is not fluorinated at the α position. , Will release α-position unfluorinated sulfonic acid or carboxylic acid. Sulfonic acids and carboxylic acids that are not fluorinated at the α position will not cause deprotection reactions, so they function as quenchers.

As such a quencher, for example, a compound represented by the following formula (B) (an onium salt of a sulfonic acid that is not fluorinated at the α-position) and a compound represented by the following formula (C) (an onium salt of a carboxylic acid). [化90]

In formula (B), R ¹⁰¹ is a hydrogen atom or a hydrocarbon group with 1-40 carbon atoms that may also contain heteroatoms, but the hydrogen atom bonded to the carbon atom at the α position of the sulfo group has been replaced by a fluorine atom or a fluoroalkyl group except.

The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, n-butyl, second butyl, tertiary butyl, tertiary pentyl, n-pentyl, n-hexyl, n-octyl, 2 -Ethylhexyl, n-nonyl, n-decyl and other alkyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl , Cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 ^2,6 ]decyl, adamantyl, adamantylmethyl and other cyclic saturated hydrocarbon groups; for alkenyl, such as vinyl, allyl Alkenyl, propenyl, butenyl, hexenyl and other alkenyl groups; cyclohexenyl and other cyclic unsaturated aliphatic hydrocarbon groups; phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methyl) Phenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), dialkylphenyl (2,4-dimethylphenyl) Phenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethyl, etc.) Aryl groups such as naphthyl, etc.; heteroaryl groups such as thienyl; aralkyl groups such as benzyl, 1-phenylethyl, 2-phenylethyl, and the like.

In addition, part of the hydrogen atoms of these groups may be substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, and some of the carbon atoms of these groups may be substituted with oxygen atoms, sulfur atoms, nitrogen atoms, etc. The heteroatom group, as a result, may also contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, and the like. Hydrocarbon groups containing heteroatoms include: 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-third Alkoxyphenyl such as butoxyphenyl and 3-tertiary butoxyphenyl; Alkoxy groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, n-butoxynaphthyl, etc. Naphthyl; dialkoxynaphthyl such as dimethoxynaphthyl and diethoxynaphthyl; 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-side Oxyethyl, 2-(2-naphthyl)-2-oxyethyl and other aryl-side oxyalkyl groups such as 2-aryl-2-oxyethyl and the like.

In the formula (C), R ¹⁰² is a hydrocarbon group with 1 to 40 carbon atoms that may also contain heteroatoms. As the hydrocarbon group represented by ^{R 102} , the same hydrocarbon groups as those exemplified for the hydrocarbon group represented by ^{R 101 can be cited.} In addition, other specific examples include: trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, 2,2,2-trifluoro-1- Fluorine-containing alkyl groups such as (trifluoromethyl)-1-hydroxyethyl; fluorine-containing aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

In formulas (B) and (C), Mq ⁺ is an onium cation. The aforementioned onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. As the cation or the iodonium cation, the same cations as those exemplified for the cation of the amenium salt represented by the formula (A-1) and the same cations as those exemplified for the cation of the iodonium salt represented by the formula (A-2) can be cited, respectively.

The quenching agent may further include polymer quenching agents described in Japanese Patent Application Laid-Open No. 2008-239918. After the resist material is coated, it will be aligned on the surface of the resist film, thereby improving the rectangularity of the patterned resist film. The polymer quencher also has the effect of preventing the film loss of the pattern and the rounding of the top of the pattern when the protective film for immersion exposure is used.

In the resist material of the present invention, the content of the quencher relative to 100 parts by mass of the base polymer is preferably 0-5 parts by mass, and more preferably 0-4 parts by mass.

The resist material of the present invention may also be blended with a water repellency improver to improve the water repellency of the surface of the resist film. The aforementioned water repellency improver can be used for immersion lithography that does not use a top coat. The aforementioned water repellency improver is preferably a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue with a specific structure, etc., which are published by Japan The ones exemplified in 2007-297590 and Japanese Patent Laid-Open No. 2008-111103 are preferable. The aforementioned water repellency improver must be dissolved in an alkali developer or an organic solvent developer. The aforementioned specific water repellency improver having 1,1,1,3,3,3-hexafluoro-2-propanol residues has good solubility in the developer. As a water repellency improver, a polymer containing repeating units of an amine group and an amine salt has a high effect of preventing the evaporation of the acid in the PEB and preventing poor opening of the hole pattern after development. In the resist material of the present invention, the content of the aforementioned water repellency improver relative to 100 parts by mass of the base polymer is preferably 0-20 parts by mass, more preferably 0.5-10 parts by mass. The aforementioned water repellency improvers can be used singly or in combination of two or more kinds.

Acetylene alcohols can also be blended in the resist material of the present invention. Examples of the aforementioned acetylene alcohols include those described in paragraphs [0179] to [0182] of JP 2008-122932 A. In the resist material of the present invention, the content of acetylene alcohols is preferably 0-5 parts by mass relative to 100 parts by mass of the base polymer.

[Pattern Formation Method] When the resist material of the present invention is used in the manufacture of various integrated circuits, a well-known lithography technique can be used. For example, as for the pattern formation method, a method including the following steps: forming a resist film on a substrate using the aforementioned resist material; exposing the aforementioned resist film with high-energy rays; and using a developer to expose the aforementioned exposed resist film The resist film is developed.

First, the resist material of the present invention is applied to the product in such a way that the coating film thickness becomes 0.01-2μm by using appropriate coating methods such as spin coating, roll coating, flow coating, dip coating, spray coating, and knife coating. Substrates for body circuit manufacturing (Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or substrates for mask circuit manufacturing (Cr, CrO, CrON, MoSi ₂ , SiO ₂ Wait) on. It is pre-baked on a hot plate, preferably at 60-150°C for 10 seconds to 30 minutes, more preferably at 80-120°C, 30 seconds to 20 minutes, to form a resist film.

Then, high-energy rays are used to expose the aforementioned resist film. The aforementioned high-energy rays include ultraviolet rays, extreme ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, and the like. If ultraviolet, extreme ultraviolet, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. are used as the aforementioned high-energy rays, use a mask to form the target pattern to make the exposure more It is preferably about 1 to 200 mJ/cm ² , and more preferably about 10 to 100 mJ/cm ² for irradiation. If EB is used as a high-energy ray, the exposure amount is preferably about 0.1 to 1,000 μC/cm ² , more preferably about 0.5 to 200 μC/cm ² , and drawing is performed directly or using a mask for forming a target pattern. In addition, the resist material of the present invention is particularly suitable for the use of i-rays with a wavelength of 365 nm in high-energy rays, KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchronous The micro-patterning by radiation is particularly suitable for the micro-patterning by EB or EUV.

After exposure, it can also be carried out on a hot plate or oven, preferably at 50-150°C, 10 seconds to 30 minutes, more preferably 60-120°C, 30 seconds to 20 minutes, PEB.

After exposure or PEB, use 0.1-10 mass%, preferably 2-5 mass% of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) ), Tetrabutylammonium Hydroxide (TBAH) and other alkaline aqueous solution developer, using dipping (dip) method, immersion (puddle) method, spraying (spray) method and other common methods for the exposed resist film for 3 seconds ~3 minutes, preferably 5 seconds~2 minutes of development, thereby forming the target pattern. In the case of a positive resist material, the irradiated part is dissolved in the developer, and the unexposed part does not dissolve, and the intended positive pattern is formed on the substrate. In the case of a negative type resist material, contrary to the case of a positive type resist material, the illuminated part is insoluble in the developer, and the unexposed part dissolves.

It is also possible to use a positive resist material containing a base polymer containing an acid-labile group, and use organic solvent development to implement negative development to obtain a negative pattern. The developer used at this time can include: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, Methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate , Isobutyl formate, pentyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, 3-ethoxy Ethyl propionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyl Ethyl acetate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate Ester, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents may be used individually by 1 type, and may mix and use 2 or more types.

Rinse is carried out at the end of development. The eluent is preferably a solvent that is miscible with the developer and does not dissolve the resist film. For such solvents, alcohols with 3 to 10 carbons, ether compounds with 8 to 12 carbons, alkanes, alkenes, alkynes, and aromatic solvents with 6 to 12 carbons are suitable.

Specifically, alcohols with 3 to 10 carbon atoms include: n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol , 3-pentanol, tertiary pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1 -Hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2- Butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1- Pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3- Pentanol, cyclohexanol, 1-octanol, etc.

Ether compounds with 8 to 12 carbon atoms include: di-n-butyl ether, diisobutyl ether, di-second butyl ether, di-n-pentyl ether, diisopentyl ether, di-second pentyl ether, di-third pentyl ether, di N-hexyl ether and so on.

Alkanes with 6 to 12 carbon atoms include: hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, Methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of olefins having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

Examples of aromatic solvents include toluene, xylene, ethylbenzene, cumene, tertiary butylbenzene, mesitylene and the like.

By performing rinsing, the collapse of the resist pattern and the occurrence of defects can be reduced. Furthermore, rinsing is not necessary, and the amount of solvent used can be reduced by not performing rinsing.

Thermal flow, RELACS technology or DSA technology can also be used to shrink the developed hole pattern and trench pattern. A shrinking agent is coated on the hole pattern, and the acid catalyst from the resist layer diffuses during baking, and crosslinking of the shrinking agent is initiated on the surface of the resist, and the shrinking agent will adhere to the sidewall of the hole pattern. The baking temperature should be 70~180℃, more preferably 80~170℃, and the baking time should be 10~300 seconds to remove excess shrinking agent and shrink the hole pattern. [Example]

Hereinafter, synthesis examples, examples, and comparative examples are given to specifically explain the present invention, but the present invention is not limited to the following examples.

The structures of the acid generators PAG1~PAG21 of sulfonium salt or sulphur salt used in the resist material are shown below. PAG1~PAG21 are synthesized by ion exchange of fluorinated sulfonic acid ammonium salt containing iodobenzamide group, which provides the following anions, and ion exchange of sulfonium chloride or iodonium chloride, which provides the following cations. [化91]

[化92]

[化93]

[化94]

[Synthesis example] Synthesis of base polymer (Polymers 1 to 4) Combine each monomer and carry out a copolymerization reaction in THF as a solvent, crystallize in methanol, and repeat washing with hexane, and then carry out a single After separation and drying, the base polymer (Polymer 1~4) of the following composition is obtained. The composition of the obtained base polymer was ^{confirmed by 1} H-NMR, and the Mw and Mw/Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[化95]

[Examples 1~24, Comparative Examples 1~4] Preparation and evaluation of resist materials (1) Preparation of resist material A solution obtained by dissolving each component in the composition shown in Tables 1 and 2 in a solvent of Polyfox PF-636 manufactured by Omnova as a surfactant dissolved in 100 ppm was filtered with a 0.2 μm size filter to prepare Obtain the resist material. In addition, the resist compositions of Examples 1 to 23 and Comparative Examples 1 and 2 were of positive type, and the resist compositions of Example 24 and Comparative Examples 3 and 4 were of negative type.

In Table 1, the components are as follows. Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) CyH (Cyclohexanone) PGME (Propylene Glycol Monomethyl Ether) DAA (Diacetone Alcohol)

Comparison of acid generators: comparison of PAG1 and 2 [化96]

Quencher: Quencher 1, 2 [化97]

(2) EUV lithography evaluation The resist materials shown in Tables 1 and 2 were spin-coated on the silicon-containing spin-coated hard mask SHB-A940 (silicon content: 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. with a film thickness of 20 nm. On the Si substrate, use a hot plate to pre-bake at 105°C for 60 seconds to prepare a resist film with a film thickness of 50nm. It was exposed using the EUV scanning exposure machine NXE3300 made by ASML (NA0.33, σ0.9/0.6, quadrupole illumination, and a mask with a hole pattern of 46nm pitch and +20% deviation on the wafer). Perform PEB for 60 seconds at the temperature described in Tables 1 and 2 on the hot plate, and develop with a 2.38% by mass TMAH aqueous solution for 30 seconds. In Examples 1 to 23 and Comparative Examples 1 and 2, a hole pattern with a size of 23 nm was obtained. In Example 24 , Comparative Examples 3 and 4 obtain dot patterns with a size of 23 nm. Using Hitachi High-Technologies (stock) length measuring SEM (CG5000), measure the exposure when forming holes or dots and define it as sensitivity, measure the size of 50 holes or dots and find the dimensional variation (CDU, 3σ) . The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

From the results shown in Tables 1 and 2, it can be seen that the resist material of the present invention containing the iodinated benzamide group-containing fluorinated sulfonic acid salt or iodonium salt as an acid generator is highly sensitive and has a good CDU.

without

Claims (13)

A resist material, comprising: a base polymer, and an acid generator, including a sulfonium salt represented by the following formula (A-1) or an iodonium salt represented by the following formula (A-2);

In the formula, m and n are integers satisfying 1≦m≦5, 0≦n≦3, and 1≦m+n≦5; p is an integer satisfying 1≦p≦3; L ¹ is single when p is 1. A bond or a bivalent linking group with 1-20 carbons. When p is 2 or 3, it is a trivalent or tetravalent linking group with 1-20 carbons. The linking group may also contain an oxygen atom, a sulfur atom or a nitrogen atom; Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group; in addition, Rf ¹ and Rf ² may be combined to form a carbonyl group; R ¹ is a hydroxyl group; R ² is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms; in addition, R ² and L ¹ may also be bonded to each other and form a ring together with the nitrogen atom to which they are bonded; R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a hydrocarbon group with a carbon number of 1 to 20 which may also contain heteroatoms; in addition, R ³ and R ⁴ may also be bonded to each other and form a ring with the sulfur atom to which they are bonded . For example, the resist material of claim 1 further contains organic solvents. The resist material of claim 1 or 2, wherein the base polymer comprises a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; X ¹ is a single bond, a phenylene group or a naphthylene group, or a linking group containing an ester bond, an ether bond or a lactone ring with carbon numbers of 1-12; X ² is a single bond or an ester bond; X ³ is a single bond, an ether bond or an ester bond; R ¹¹ and R ¹² are acid labile groups; R ¹³ is a fluorine atom, trifluoromethyl, cyano group, carbon number 1~ 6 saturated hydrocarbyl groups, saturated hydrocarbyloxy groups with 1 to 6 carbons, saturated hydrocarbyl carbonyl groups with 2 to 7 carbons, saturated hydrocarbyl carbonyloxy groups with 2 to 7 carbons, or saturated hydrocarbyloxycarbonyl groups with 2 to 7 carbons; R ¹⁴ is a single bond or an alkanediyl group with 1 to 6 carbon atoms, part of the carbon atoms may be substituted with ether bonds or ester bonds; a is 1 or 2; b is an integer of 0-4. For example, the resist material of claim 3 further contains a dissolution inhibitor. For example, the resist material in claim 3 is a chemically amplified positive resist material. The resist material of claim 1 or 2, wherein the base polymer does not contain an acid labile group. For example, the resist material of claim 6 further contains a cross-linking agent. For example, the resist material in claim 6 is a chemically amplified negative resist material. For example, the resist material of claim 1 or 2 further contains a surfactant. The resist material of claim 3, wherein the base polymer further contains at least one of the repeating units represented by the following formulas (f1) to (f3);

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, a phenylene group, -OZ ¹¹ -, -C(=O)-OZ ¹¹ -or -C(=O)-NH- Z ¹¹ -; Z ¹¹ is aliphatic alkylene group, phenylene group, naphthylene group with carbon number 1 to 6, or a combination of these, and the group with carbon number 7 to 18, and can also contain carbonyl group, ester group, ether or a hydroxyl group; Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 is a carbon number of 1 to 12 Saturated alkylene group may also contain carbonyl, ester bond or ether bond; Z ³ is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, -OZ ³¹ -, -C(=O) -OZ ³¹ -or -C(=O)-NH-Z ³¹ -, Z ³¹ is aliphatic alkylene group, phenylene group, fluorinated phenylene group with carbon number 1~6, or substituted with trifluoromethyl The phenylene group may also contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group; R ²¹ to R ²⁸ are each independently a hydrocarbon group of 1 to 20 carbons that may also contain heteroatoms; and R ²³ and R ²⁴ , or R ²⁶ and R ²⁷ can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded; R ^HF is a hydrogen atom or a trifluoromethyl group; M ^{-is a} non-nucleophilic counter ion. A pattern forming method includes the following steps: forming a resist film on a substrate using a resist material as claimed in any one of claims 1 to 10; exposing the resist film with high-energy rays; and using a developer to form a resist film on the substrate. The exposed resist film is developed. The pattern forming method of claim 11, wherein the high-energy ray is ArF excimer laser light with a wavelength of 193 nm or KrF excimer laser light with a wavelength of 248 nm. The pattern forming method of claim 11, wherein the high-energy rays are electron beams or extreme ultraviolet rays with a wavelength of 3-15 nm.